Bowling Swing Bridge

1897

1897

at Bowling, east of Dumbarton

See Geograph entry.

Constructed for the Lanarkshire and Dumbartonshire Railway to carry a double-track railway across the mouth of the Forth and Clyde Canal basin at Bowling.

1897 '... the tail of the bridge is unusually short, little over one-third of the nose portion, whereas the usual practice is one-half. This enables the bridge to be rotated much more rapidly than would otherwise be the case, the momentum being more easily controlled. This, however, involved an increase in the weight of kentledge, there being 145 tons, while the whole moving load is 380 tons. ...'. Charles Forman was the Engineer.

The hydraulic equipment, produced by the Glenfield Co, was described in detail and illustrated in Engineering 1897/06/18. For turning, the bridge was raised by a 38.5" diameter hydraulic ram at the centre pivot, and two rail rams with rollers to support the counterpoise. Two horizontal rams provided the turning force, acting via connecting rods with ball-and-socket ends. There are also auxiliary vertical rams, 28" diameter, with tandem rollers able to carry the whole weight of the bridge. They were normally clear, and only intended to act if the bridge tilted in high winds or if the main ram failed. The disposition of the rams is shown in the part copy of the adjacent drawing.

The hydraulic pressure for operating the machinery was generated by a 50 horse-power engine working at 100 rpm. The diameter of the two steam cylinders is 14 in., and the stroke 16 in., while there were four water cylinders, each 2 3/8 in. in diameter. There were two boilers giving a steam pressure was 100 lb., and the engines gave a supply of 60 gpm at 900 psi. The bridge could be lifted in 6 seconds and rotated in 32 seconds.

The bridge no longer swings. All equipment has been removed from the pumphouse, as has the turning machinery. However, the main rams for lifting the bridge prior to the swinging procedure are still in position.

See Also

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